Method and apparatus for measuring the reaction of an indicator to the presence of various gases

• US 4,806,491 A
• Filed: 12/01/1986
• Issued: 02/21/1989
• Est. Priority Date: 12/07/1985
• Status: Expired due to Fees

• Current Assignee: Dragerwerk AG
• Original Assignee: Dragerwerk AG
• Inventors: Heim, Ulrich
• Primary Examiner(s): Marcus, Michael S.
• Assistant Examiner(s): WARDEN, JILL ALICE
• Application Number:
  US06/936,182
• Time in Patent Office: 813 Days
• Field of Search: 422/58, 422/87, 436/165
• US Class Current: 436/165
• CPC Class Codes: G01N 21/783 for analysing gases

Abstract

A process for the measuring of flat discoloration zones of an indicator substrate, which is transported into a measuring position and treated with a gaseous test medium there, is improved with regard to the measuring dynamic and the construction of the apparatus by producing a flow of the test medium along the surface of the section of an indicator substrate held in a measuring position, by providing several optical control zones staggered in the longitudinal direction of the test flow and by connecting it with an electronic evaluation instrument for the production of the measurement in such a way that the actual measure value is formed from the measuring of the discoloration of the indicator substrate along the control zones.

Claims

1. A method for measuring the reaction of an indicator to various gases, comprising:

positioning an indicator strip in a longitudinally elongated measuring chamber, the indicator including flat areas of discoloration reaction zones and being provided on a movable indicator substrate said step of positioning comprising transporting said substrate to a measuring position within the chamber;

directing a gas to be measured into one end of the measuring chamber and withdrawing the gas at the opposite end thereof;

employing a plurality of indicator sensors along the length of the chamber to electro-optically measure the reaction by the changes in color of said reaction zones of the indicator strip to the gas flow along the length of the chamber;

measuring said reaction in a measuring cycle using an electronic evaluating instrument connected to the sensors, by creating a surface measuring flow of the test gas medium along the surface of a section of the indicator substrate while the indicator is held firmly in a measuring position staggering several optical control zones in a selected direction of the measuring flow;

providing and connecting the zones with electronic evaluating instruments for the performance of the measurement which measures discolorations of the indicative substrate along the controlled zones; and

, measuring the length of the discoloration zone.

2. A process according to claim 1 wherein the measurement is performed at least two different waves lengths.

3. A method for measuring the reaction of an indicator to various gases, comprising:

positioning an indicator strip in a longitudinally elongated measuring chamber, the indicator including flat areas of discoloration reaction zones and being provided on a movable indicator substrate said step of positioning comprising transporting said substrate to a measuring position within the chamber;

directing a gas to be measured into one end of the measuring chamber and withdrawing the gas at the opposite end thereof;

employing a plurality of indicator sensors along the length of the chamber to electro-optically measure the reaction by the change in color of said reaction zones of the indicator strip to the gas flow along the length of the chamber;

measuring said reaction in a measuring cycle using an electronic evaluating instrument connected to the sensors, by creating a surface measuring flow of the test gas medium along the surface of a section of the indicator subtrate while the indicator is held firmly in a measuring position, staggering several optical control zones in a selected direction of the measuring flow;

providing and connecting the zones with electronic evaluating instruments for the performance of the measurement which measures discolorations of the indicative substrate along the controlled zones; and

, performing an integral measurement over the length of the discoloration zone.